Fluorosulfates of hexafluoroisobutylene and its higher homologs and their derivatives

ABSTRACT

Hexafluoroisobutylene and its higher homologs are easily reacted with SO 3  to give fluorosulfates of the formula CH 2 ═C(R)CF 2 OSO 2 F, wherein R is a linear branched or cyclic fluoroalkyl group comprised of 1 to 10 carbon atoms and may contain ether oxygen. These compounds react under mild conditions with many nucleophiles to give CH 2 ═C(R)CF 2 X, where X is derived from the nucleophile. This reaction provides a route to many substituted hexafluoroisobutylenes, which copolymerize easily with other fluoro- and hydrocarbon monomers such as vinylidene fluoride and ethylene.

FIELD OF THE INVENTION

This invention relates to the synthesis of fluoroolefins.

BACKGROUND OF THE INVENTION

Hexafluoroisobutylene's utility is shown by the variety offluoromonomers and hydrocarbon monomers with which it copolymerizes. Forexample, it copolymerizes with vinylidene fluoride (U.S. Pat. No.3,706,723), with vinyl fluoride (International Application WO2001-037043), with ethylene and tetrafluoroethylene orchlorotrifluoroethylene (European Patent No. 0 121 073 B1), withtrifluoroethylene (International Application WO 2001-037043), and withtetrafluoroethylene and vinyl acetate (European Patent No. 1 169 399A2). Its utility as a component of polymers could be increased if meanscould be found to add substituents to it. For example, ifhexafluoroisobutylene could be substituted to provide functional groupssuch as acids, the monomer could be used in making fluorinatedion-exchange polymers.

SUMMARY OF THE INVENTION

In one embodiment the present invention provides a compound having theformula CH₂═C(R)CF₂OSO₂F, wherein R is a linear, branched, or cyclicfluoroalkyl group comprised of 1 to 10 carbon atoms and may containether oxygen.

In a second embodiment the present invention provides a compound havingthe formula CH₂═C(CF₂OSO₂F)₂.

In a third embodiment the present invention provides a compound havingthe formula CH₂═C(R)CF₂X, wherein R is a linear, branched, or cyclicfluoroalkyl group comprised of 1 to 10 carbon atoms and may containether oxygen, and X is selected from the group consisting of hydride,halides except fluoride, cyanide, alkoxides, fluoroalkoxides, andperfluoroalkoxides such as OCF₂CF₂SO₂F, aryl oxides, fluoroaryloxides,and perfluoroaryloxides, mercaptides, fluoromercaptides,perfluoromercaptides, secondary amines which may be fluorinated, azide,cyanate, isocyanate, thiocyanate, hydroxyalkoxides, haloalkoxides, epoxyalkoxides, cyanoalkoxides, ester alkoxides, and thiolmercaptides.

In a fourth embodiment the present invention provides a compound havingthe formula CH₂═C(CF₂X)CF₂X′, wherein X and X′ are independentlyselected from the group consisting of hydride, halides except fluoride,cyanide, alkoxides, fluoroalkoxides, and perfluoroalkoxides such asOCF₂CF₂SO₂F, aryl oxides, fluoroaryloxides, and perfluoroaryloxides,mercaptides, fluoromercaptides, perfluoromercaptides, secondary amineswhich may be fluorinated, azide, cyanate, isocyanate, thiocyanate,hydroxyalkoxides, haloalkoxides, epoxy alkoxides, cyanoalkoxides, esteralkoxides and thiolmercaptides.

In a fifth embodiment the present invention provides a processcomprising contacting CH₂═C(R)CF₃with SO₃ in the presence of a Lewisacid, wherein R is a linear, branched, or cyclic fluoroalkyl groupcomprised of 1 to 10 carbon atoms and may contain ether oxygen, toproduce a CH₂═C(R)CF₃/SO₃ adduct. A preferred compound of the formulaCH2═C(R)CF₃ for use in this process is hexafluoroisobutylene (R is CF₃).

In a sixth embodiment the present invention provides a processcomprising contacting CH₂═C(R)CF₂OSO₂F with a first nucleophile, whereinR is a linear, branched, or cyclic fluoroalkyl group comprised of 1 to10 carbon atoms and may contain ether oxygen, to produce a substitutionproduct. Preferred nucleophiles are selected from the group consistingof hydride, halides, cyanide, alcohols, alkoxides, fluoroalkoxides, andperfluoroalkoxides such as ⁻OCF₂CF₂SO₂F, aryl oxides, fluoroaryloxides,and perfluoroaryloxides, mercaptides, fluoromercaptides,perfluoromercaptides, secondary amines which may be fluorinated, azide,cyanate, isocyanate, thiocyanate, hydroxyalkoxides, haloalkoxides, epoxyalkoxides, cyanoalkoxides, ester alkoxides and thiolmercaptides.

In a seventh embodiment the present invention provides a processcomprising contacting CH₂═C(CF₂OSO₂F)₂ with a first nucleophile and thenwith a second nucleophile, different from said first nucleophile toproduce a substitution product.

In an eighth embodiment the present invention provides copolymers ofCH₂═C(R)CF₂X, wherein R is a linear, branched, or cyclic fluoroalkylgroup comprised of 1 to 10 carbon atoms and may contain ether oxygen,and X is selected from the group consisting of hydride, halides exceptfluoride, cyanide, alkoxides, fluoroalkoxides, and perfluoroalkoxides,aryl oxides, fluoroaryloxides, and perfluoroaryloxides such asOCF₂CF₂SO₂F, mercaptides, fluoromercaptides, perfluoromercaptides,secondary amines which may be fluorinated, azide, cyanate, isocyanate,thiocyanate, hydroxyalkoxides, haloalkoxides, epoxy alkoxides,cyanoalkoxides, ester alkoxides, and thiolmercaptides, and at least oneother monomer.

In a ninth embodiment the present invention provides a compound havingthe formula CF₂═C(R)CH₂X, wherein R is a linear, branched, or cyclicfluoroalkyl group comprised of 1 to 10 carbon atoms and may containether oxygen, and X is selected from the group consisting of hydride,halides except fluoride, cyanide, alkoxides, fluoroalkoxides, andperfluoroalkoxides such as OCF₂CF₂SO₂F, aryl oxides, fluoroaryloxides,and perfluoroaryloxides, mercaptides, fluoromercaptides,perfluoromercaptides, secondary amines which may be fluorinated, azide,cyanate, isocyanate, thiocyanate, hydroxyalkoxides, haloalkoxides, epoxyalkoxides, cyanoalkoxides, ester alkoxides and thiolmercaptides.

In a tenth embodiment the present invention provides compound having theformula CF₂═C(CF₂X)CH₂X′ wherein X and X′ are independently selectedfrom the group consisting of hydride, halides except fluoride, cyanide,alkoxides, fluoroalkoxides, and perfluoroalkoxides such as OCF₂CF₂SO₂F,aryl oxides, fluoroaryloxides, and perfluoroaryloxides, mercaptides,fluoromercaptides, perfluoromercaptides, secondary amines which may befluorinated, azide, cyanate, isocyanate, thiocyanate, hydroxyalkoxides,haloalkoxides, epoxy alkoxides, cyanoalkoxides, ester alkoxides andthiolmercaptides .

DETAILED DESCRIPTION

Hexafluoroisobutylene has been discovered to react easily with sulfurtrioxide (SO₃) in the presence of a Lewis acid to yield ahexafluoroisobutylene/SO₃ adduct, CH₂═C(CF₃)CF₂OSO₂F, referred to hereinas hexafluoroisobutylene fluorosulfate or HFIBFS. Suitable Lewis acidsinclude BF₃, B(OCH₃)₃, SbF₅, SbCl₅, BCl₃, B(OC(═O)CF₃)₃, B(OSO₂CF₃)₃,B₂O₃, H₃BO₃, and Na₂B₄O₇ (It is recognized that Na₂B₄O₇ is not in itselfa Lewis acid. However, it behaves like a Lewis acid in the presence ofSO₃.). Preferred Lewis acids are BF₃, B(OCH₃)₃, and SbF₅. Reactiontemperature is in the range of about −50 to 100° C., preferably about−25 to 75° C., more preferably about 0 to 50° C., still more preferablyabout 10 to 40° C., and most preferably about 20 to 30° C. Withoccasional or continuous stirring or agitation, a satisfactory yield ofHFIBFS is obtained in about 1 minute and greater, preferably about 1minute to about 100 hours.

In addition to HFIBFS, the reaction of hexafluoroisobutylene with SO₃can also be made to yield the diadduct, CH₂═C(CF₂OSO₂F)₂, referred toherein as hexafluoroisobutylene difluorosulfate or HFIBFS2.CH₂═C(CF₂OSO₂F)₂ is produced by increasing the molar ratio of SO₃ tohexafluoroisobutylene to greater than 1. Yields of the difluorosulfateare increased as the SO₃ to hexafluoroisobutylene molar ratio isincreased. At a molar ratio of greater than 2, difluorosulfate can beexpected to be the predominant product.

The reaction with SO₃ is not limited to hexafluoroisobutylene, but willtake place generally with olefins of the class CH₂═C(CR)CF₃ to produce aCH₂═C(CR)CF₃/SO₃ adduct, wherein R is a fluoroalkyl group, preferably aperfluoroalkyl group of from 1 to about 10 carbons, linear, cyclic, orbranched. The alkyl group may contain ether oxygen. A member of thisclass is CH₂═C(C₂F₅)CF₃. Its reaction with SO₃ to giveCH₂═C(C₂F₅)CF₂OSO₂F is disclosed in the Examples.

The term “fluorosulfate” is used herein to refer to HFIBFS, HFIBFS2,CH₂═C(C₂F₅)CF₂OSO₂F, and compounds of the general formula above,CH₂═CRCF₂OSO₂F.

The fluorosulfates described above, HFIBFS, HFIBFS2, and CH₂═CRCF₂OSO₂F,have been found to react with nucleophiles to yield substitutionproducts, i.e., compounds of the general formula CH₂═C(R)CF₂X andCH₂═C(CF₂X)₂ (from HFIBFS2), where X is the substituent characteristicof the nucleophile. For example, if the nucleophile is the chloride ion,then reaction gives CH₂═C(R)CF₂Cl. The reaction proceeds under mildconditions, an indication that the fluorosulfate group (—OSO₂F) is aneffective “leaving group”, that is, it is easily displaced bynucleophiles.

Nucleophiles are atoms or groups of atoms that have unbonded, also knownas “free”, electron pairs. They may be neutral, amines are examples, oranionic, such as halides. Nucleophiles react with susceptible molecules,attacking, for example, saturated carbon atoms, displacing an atom orgroup of atoms, the nucleophile thereby becoming bonded to the saturatedcarbon atom. A discussion of nucleophiles can be found in AdvancedOrganic Chemistry, 4^(th) edition, by Jerry March, Wiley, N.Y., 1992, p.205.

Among the nucleophiles suitable for reaction with fluorosulfates are thehalides, alcohols, for example, methanol, alkoxides, for examplemethoxide (CH₃O⁻), fluoroalkoxides, for example CF₃CH₂O⁻, andperfluoroalkoxides, for example (CF₃)₂CFO³¹ , and⁻OCF₂(CF(CF₃)—O—CF₂)_(n)CF₂SO₂F where n=0-5, aryl oxides,fluoroaryloxides, and perfluoroaryloxides, for example C₆F₅O⁻,mercaptans, fluoromercaptans, perfluoromercaptans, secondary amineswhich may be fluorinated, and hydrides, such as sodium borohydride andlithium aluminum hydride. It will be recognized by the skilled artisanthat perfluoralkoxides are prepared, preferably in situ, from thecorresponding perfluoroketones or perfluoroacid fluorides by reactionwith fluoride ion, usually from potassium fluoride (KF). For alkoxidesderived from alcohols, such as methanol and hexafluoroisopropyl alcohol,it is not necessary that they be converted to their alkali metal saltsto be effective in the reaction according to this invention. The alcoholmay be used directly, preferably with added tertiary amine to promotereaction. The anionic nucleophiles are of course accompanied by cations,that is they are salts. The cations are preferably alkali metal cations,chosen so that the salt will be reasonably soluble in the reactionmedium. Preferred nucleophiles are halides, more preferably chloride,bromide, and iodide; cyanide, alcohols, alkoxides, fluoroalkoxides,perfluoroalkoxides, aryloxide, fluoroaryloxides, andperfluoroaryloxides. Further preferred nucleophiles are substitutedalcohols such as ethylene cyanohydrin (HOCH₂CH₂CN), glycidol(2,3-epoxypropanol), ethylene halohydrin (XCH₂CH₂OH) such as ethylenechlorohydrin, ethylene bromohydrin, and ethylene iodohydrin, which willprovide substituted hexafluoroisobutylene with cyano, epoxy, and halogenfunctionality. These may also be described as cyanoalkoxides,epoxyalkoxides and haloalkoxides, in keeping with the alkoxideterminology used above, and will be understood to include higheralkylene groups, that may be fluorinated, in addition to the two- andthree-carbon molecules described above. Similarly carboxylatefunctionality can be introduced preferably through the esters thereofthrough use of hydroxy-substituted organic esters, such as the methylester of glycolic acid. These are referred to herein as ester alkoxides.The acids may contain fluorine.

Further preferred nucleophiles are glycols (which are designated hereinas hydroxyalkoxides, in keeping with the alkoxide terminology usedabove), and dithiols, referred to herein as thiolmercaptides, forexample HSCH₂CH₂S⁻, to provide thiol functionality.

The various functionalities provided by the above nucleophiles,particularly the epoxy, hydroxy, amino, cyano, and thiol functionalitiesconfer useful properties on polymers incorporating as comonomers one ormore compounds in accordance with the invention containing thesefunctionalities. These useful properties include cross-linkability,dyeability, adhesion to other materials, such as metals and glass andpolar polymers such as polyamides and polyesters. Improved adhesion isuseful in fluoropolymers in multilayer structures. Often poor adhesionby the fluoropolymer layer to non-fluoropolymer layers necessitates theuse of an interlayer or adhesive. Incorporation of a comonomer thatconfers adhesive properties on the copolymer can obviate the interlayersand adhesives. These functional groups can also be grafting sites forthe attachment of small molecules or large molecules, such as polymers,to modify a copolymer that incorporates as comonomers one or morecompounds of this invention.

A particularly useful perfluoroalkoxy nucleophile is⁻OCF₂(CF(CF₃)—O—CF₂)_(n)CF₂SO₂F where n=0-5, made according to thedisclosures of U.S. Pat. No. 3,301,893. This is prepared from thecorresponding carbonyl fluoride, exemplified here for n=0:F(O)CF₂CF₂SO₂F and KF. ⁻OCF₂CF₂SO₂F reacts with HFIBFS or HFIBFS2 togive CH₂═C(CF₃)OCF₂CF₂SO₂F and CH₂═C(OCF₂CF₂SO₂F)₂, respectively. Thefluorosulfonate functionality of these molecules, i.e. the —SO₂F, can behydrolyzed to give the —SO₃H functionality. This strong acid group is aneffective catalyst and ion-exchange group. Therefore by polymerizationof CH₂═C(CF₃)OCF₂CF₂SO₂F with vinylidene fluoride or other appropriatemonomers gives a polymer that after hydrolysis, has ion-exchangecharacter, and is suitable for example, in membranes for batteries, fuelcells, and other electrochemical applications. Similarly,copolymerization of CH₂═C(OCF₂CF₂SO₂F)₂ gives a polymer in which theion-exchange groups are “paired”, giving a bidentate ligand character tothe polymer. Such polymers may be expected to show unusual ion-exchangeand sequestering characteristics. Hydrolysis of these sulfonyl fluoridecontaining polymers can be done in aqueous dimethyl sulfoxide (DMSO)with potassium hydroxide (KOH). A typical recipe is 15% water, 60% DMSO,and 15% KOH. One hour at 70-90° C. is sufficient. The polymer is washedfree of salts and DMSO. At this point the polymer is in the potassiumion form, that is, it is a polymer containing potassium sulfonategroups. Acid exchange, for example by treating it several times with 1 Naqueous hydrochloric or nitric acid, converts the polymer to thesulfonic acid form. A milder hydrolysis method, preferred for polymersthat contain both hydrogen and fluorine on their carbon backbones, usesammonium carbonate as the base under milder conditions and is disclosedin U.S. Patent Application Publication No. 2003/0013816. For polymersintended for lithium battery use, the lithium salt of the ionomer can bedirectly made using lithium carbonate as the base as disclosed in U.S.Pat. No. 6,140,436.

A related perfluoroalkoxy nucleophile that can confer ion-exchangeproperties on polymer and act as a reactive site is⁻OCF₂—(CF(CF₃)—O—CF₂)_(n)—CF₂COOR, where R is an alkyl group of 1 to 5carbon atoms, and n=0-6. This is prepared fromF(O)C—(CF(CF₃)—O—CF₂)_(n)—CF₂COOR and KF. The acid fluorides areprepared as disclosed in U.S. Pat. No. 4,131,740

The reaction of HFIBFS2 with nucleophiles can be tailored to providemixed substitution. That is, in the resulting molecule CH₂═C(CF₂X)₂, theX groups need not be identical. Such a molecule with nonidentical Xs canbe represented as CH₂═C(CF₂X)CF₂X′. One way to promote mixedsubstitution is to limit the concentration in the reaction medium of thefirst nucleophile to no more than equimolar with HFIBFS2, and then,after the reaction is complete, to add the second nucleophile.

Compatible solvents, preferably aprotic polar solvents, areadvantageously used as the reaction medium for the reaction offluorosulfates with nucleophiles. Diglyme (bis(2-methoxyethyl) ether),diethyl ether, tetrahydrofuran, sulfolane, acetonitrile,N,N-dimethylformamide, and N,N-dimethylacetamide are more preferred.Diglyme is most preferred. Protic solvents are generally not preferredunless reaction of solvent with the fluorosulfate can be tolerated or isdesired.

Temperature for the reaction of fluorosulfates with nucleophiles is inthe range of about −25 to 100° C., preferably about 0 to 50° C., morepreferably about 15 to 30° C., and most preferably about 20 to 30° C.

In addition to the reaction products having methylene, i.e. CH₂═,functionality, isomers are formed also having difluoromethylenefunctionality. For example, reaction of HFIBFS with chloride ion givesCH₂═C(CF₃)CF₂Cl (the methylene isomer) and also CF₂═C(CF₃)CH₂Cl (thedifluoromethylene isomer). The ratio of the methylene isomer to thedifluoromethylene isomer is affected by reaction conditions. In thereaction of HFIBFS with chloride ion, longer reaction time increases theyield of CH₂═C(CF₃)CF₂Cl and decreases the yield of CF₂═C(CF₃)CH₂Cl, asis shown in Example 17. For the purposes of polymerization, themethylene isomer is more desirable.

Compounds described herein, CH2═C(R)CF2X and CH2═C(CF2X)CF2X′, where Xand X′ are the same or different and represent the substituentsdisclosed above, are suitable for polymerization. Particularly suitedare the compounds in which X and X′ are selected from the group hydride,halides except fluoride, alkoxides, fluoroalkoxides, andperfluoroalkoxides such as OCF₂CF₂SO₂F, mercaptides, fluoromercaptides,perfluoromercaptides, secondary amines which may be fluorinated, azide,hydroxyalkoxides, haloalkoxides, preferably chloroalkoxides, esteralkoxides.

As noted in the Background, experience shows that hexafluoroisobutylenecopolymerizes with many monomers, both fluoromonomers, defined herein asmonomers having at least one fluorine atom bonded to a doubly bondedcarbon atom, and olefinic hydrocarbon monomers. These monomers aresuitable for making copolymers in accordance in accordance with theinvention and include vinyl fluoride, vinylidene fluoride, ethylene,propylene, vinyl acetate, perfluoroalkyl ethylenes of the formulaCH₂═CH—C_(n)F_(2n+1) where n=1-10, tetrafluoroethylene,trifluoroethylene, hexafluoropropylene, chlorotrifluoroethylene, fluoro-and perfluoromonomers of the dioxole type, such as4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole, perfluoro(alkyl vinylethers) such as perfluoro(propyl vinyl ether), perfluoro(ethyl vinylether), and perfluoro(methyl vinyl ether). Preferred comonomers arevinyl fluoride, vinylidene fluoride, ethylene, propylene, vinyl acetate,and trifluoroethylene. Copolymers are defined herein as polymersresulting from the polymerization of two or more monomers.

The copolymers in accordance with this invention may be crystalline,i.e. have a melting point as measured by differential scanningcalorimetry (DSC), or may be amorphous. Amorphous polymers have utilityas components of solutions of polymer, suitable for coatings andarticles having good transparency. Amorphous polymers having low glasstransitions temperatures (Tg) are useful as elastomers, preferably withTg below about 20° C., more preferably below about 0° C., mostpreferably below about −25° C. Compounds in accordance with thisinvention include monomers with functionality suitable for crosslinkingof the kind often used in elastomer technology.

Copolymers of two of the compounds of this invention with vinylidenefluoride are described in the Examples.

EXAMPLES

Hexafluoroisobutylene preparation is disclosed in U.S. Pat. No.3,894,097. Preparation of CH₂═C(CF₃)C₂F₅(3-trifluoromethyl-1,1,1,2,2-pentafluoro-4-butene) is disclosed in theunexamined Japanese patent application (Kokai) 09077700. U.S. Pat. No.2,852,554 discloses the preparation of FSO₂CF₂COF. H-Galden® ZT 85, atrademark of Ausimont, is HCF₂O(CF₂O)_(n)(CF₂CF₂O)_(m)CF₂H. DP initiatoris hexafluoropropyleneoxide dimer peroxide:CF₃CF₂CF₂OCF(CF₃)(C═O)OO(C═O)CF(CF₃)OCF₂CF₂CF₃. Vertrel® XF, a productof E. I. du Pont de Nemours & Co., Wilmington Del. USA, isCF₃CFHCFHCF₂CF₃.

Analyses of the products of the examples is done using nuclear magneticresonance (NMR) both proton NMR (¹H) and fluorine NMR (¹⁹F) and massspectrometry (MS). Except where noted, NMR analysis is done using anexternal standard of trifluoroacetic acid or of fluorotrichloromethane(CFCl₃, F-11). In the MS results “M” represents the parent molecule. Ifno solvent is mentioned, the analysis was done on neat material.

Example 1 Preparation of Hexafluoroisobutylene Fluorosulfate(CH₂═C(CF₃)CF₂OSO₂F) Using BF₃

Hexafluoroisobutylene (60 g, 0.36 mole) and SO₃ (14 ml, 0.33 mole) thatcontains about 0.05% BF₃ are loaded into a steel autoclave. Theautoclave is closed, warmed to 18° C., and shaken for 40 hours. Then theautoclave is chilled, opened, and the contents washed with 30 ml of cold(−10° C.) concentrated sulfuric acid (H₂SO₄). The organic layer isseparated and distilled to give hexafluoroisobutylene (15 g) andCH₂═C(CF₃)CF₂OSO₂F (57.5 g, 85% yield, boiling point (b.pt.) 104-106° C.The conversion is 75%.

¹H NMR: δ 5.77 (br.s). ¹⁹F NMR δ−125 (t, (FSO₂O); −11.5 (t, (CF₃);J(FO₂SO—CF₂)=7 Hz, J(CF₃—CF₂)=7 Hz. MS (m/z, species, intensity %): 225[M-F]⁺ (<1); 161 [M-SO₂F]⁺ (12); 145 [M-OSO₂F]⁺ (100); 95 [M-C₃F₃H]⁺(16); 69 [CF₃]⁺ (20).

Example 2 Preparation of Hexafluoroisobutylene FluorosulfateCH₂═C(CF₃)CF₂OSO₂F Using SbF₅

Sulfur trioxide containing 1 wt % SbF₅ is charged to a 50 ml steel tube.The tube is then cooled to −70° C., a vacuum applied, and thenhexafluoroisobutylene (32.8 g, 0.2 mole) is added. The tube is kept at20° C. for 48 hours with periodical shaking, after which is cooled to−70° C. and opened. The reaction mixture is washed with cold (−30° C.)concentrated H₂SO₄ and then warmed to 25° C. Hexafluoroisobutylene (14g) is collected in a cold trap. The residue (15.7 g) isCH₂═C(CF₃)CF₂OSO₂F (70% yield) and a mixture of pyrosulfates of thegeneral formula CH₂═C(CF₃)CF₂(OSO₂)_(n)OSO₂F, where n=1, 2, and 3. Thebisfluorosulfate CH₂═C(CF₂OSO₂F)₂ is not detected. This exampledemonstrates the utility of SbF₅ as a catalyst for the reaction.

Example 3 Preparation of Hexafluoroisobutylene FluorosulfateCH₂═C(CF₃)CF₂OSO₂F Using B(OMe)₃

An autoclave is charged with SO₃ (28 ml), 0.3 g. trimethylborate(B(OMe)₃) and hexafluoroisobutene (130 g, 0.79 mole) The mixture isshaken at ambient temperature for 40 hours. The products from four suchreactions are combined and distilled to give hexafluoroisobutene (49 g),a mixture of hexafluoroisobutene and CH₂═C(CF₃)CF₂OSO₂F boiling below97° C. (60 g), and CH₂═C(CF₃)CF₂OSO₂F (451.4 g, 64%), b.pt. 98-108° C.This example demonstrates the utility of B(OMe)₃ as a catalyst for thereaction.

Example 4 Preparation of Hexafluoroisobutylene DifluorosulfateCH₂═C(CF₂OSO₂F)₂ Using BF₃

Hexafluoroisobutylene (96 g, 0.59 mole) and SO₃ (76 g, 0.95 mole) thatcontains abut 0.5% BF₃ are charged to a steel autoclave and stirred at18-20° C. for 72 hours. The autoclave is then cooled to −70° C. andopened. The reaction mixture is washed with cold (−20° C.) concentratedH₂SO₄. The reaction mixture is then distilled, givinghexafluoroisobutylene (13.9 g); CH₂═C(CF₃)CF₂OSO₂F (65.8 g, 53.7%);CH₂═C(CF₂OSO₂F)₂ (40.6 g, 25%), b.pt. 71-73° C. at 15 mm Hg. Thisexample shows that increasing the molar ratio of SO₃ tohexafluoroisobutylene to >1 results in production of difluorosulfate. Toincrease the amount of difluorosulfate, the SO₃ to hexafluoroisobutyleneratio need only be increased more. At a molar ratio of >2,difluorosulfate can be expected to be the predominant product.

¹H NMR of the difuorosulfate: δ 6.6 (s, CH₂). ¹⁹F NMR δ−126.7 (m,(OSO₂F); −8.6 (m, (CF₂). MS (m/z, species, intensity %): 225 [M-OSO₂F]⁺(49.9); 145 [CH₂═C(CF₃)CF₂]⁺ (95.2); 123 [C₄H₂H₃O]⁺ (100); 141 [C₄HF₄O]⁺(40.5); 95 [C₃H₂F₃]⁺ (29.5); 83 [SO₂F]⁺ (88.5); 76 [C₃H₂F₂]⁺ (40); 75[C₃HF₂]⁺ (56.2); 69 [CF₃]⁺ (25.3).

Example 5 Preparation of the Fluorosulfate of CH₂═C(CF₃)C₂F₅(3-trifluoromethyl-1,1,1,2,2-pentafluoro-4-butene) Using B(OMe)₃

3-Trifluoromethyl-1,1,1,2,2-pentafluoro-4-butene (CH₂═C(CF₃)C₂F₅) (10 g,46 mmoles), SO₃ (3.6 g, 46 mmoles, and B(OMe)₃ (1 drop) are placed in aglass tube. The tube is sealed at maintained at 18-21° C. for 7 dayswith periodic shaking. Then the tube is cooled to −70° C. and opened.The reaction mixture is washed with cold (−30° C.) concentrated H₂SO₄and distilled. 3-Trifluoromethyl-1,1,1,2,2-pentafluoro-4-butene (2 g) isrecovered and CH₂═C(C₂F₅)CF₂OSO₂F (8 g), b.pt. 137° C. Yield is 59%.This example shows that the fluorosulfonation reaction is not limited tohexafluoroisobutylene, but is effective with a higher homologue ofhexafluoroisobutylene.

^(·)F NMR: δ−126 (t, 1 ⁴F); −12 (m, 2 ³F); 8 (m, 3 ¹F); 38 (m, 2 ²F).The superscripts preceding the “F”s identify the fluorine atoms on themolecule:C¹F₃—C²F₂—C(═CH₂)—C³F₂OSO₂ ⁴F

Example 6 Reaction of CH₂═C(CF₃)CF₂OSO₂F with (CF₃)₂CFO³¹

CH₂═C(CF₃)CF₂OSO₂F (10 g, 0.041 mole) is added at 20° C. to (CF₃)₂CFOK,prepared from freshly dried potassium fluoride (KF) (2.4 g, 0.041 mole),hexafluoroacetone (HFA) (9.3 g, 0.056 mole) and dry diglyme (10 ml). Thereaction mixture is agitated for 2 hours and then poured into water, theorganic layer separating. The organic layer is washed with dilutehydrochloric acid, then sodium bicarbonate solution, then water, afterwhich it is dried over magnesium sulfate (MgSO₄). Distillation of thereaction mixture gives CH₂═C(CF₃)CF₂OCF(CF₃)₂ (10.2 g, 75% yield, b.pt.87-88° C.).

Elemental analysis: Found: C, 25.35%; H, 0.60%; F, 69.36%. Calculated:C, 25.45%; H, 0.60%; F, 69.09%. ¹H NMR (ppm): δ 5.48. ¹⁹F NMR (ppm):δ−11 (CF₃); −10 (CF₂); 5 (CF₃)₂; 69.5 (CF)₂. MS (m/z, species, intensity%): 311 [M-F]⁺ (5.5); [M-CF₃]⁺ (2.1); 169 [CF(CF₃)₂]⁺ (10.8); 145[CH₂═C(CF₃)CF₂]⁺ (100); 123 ]CH₂═C(CF₃)CO]⁺ (90); 69 [CF₃]⁺ (100).

Example 7 Reaction of CH₂═C(CF₃)CF₂OSO₂F with (CF₃)₂CFO⁻

A 250 ml flask is charged with KF (12 g) and diglyme (55 ml) in a drybox. HFA (40.5 g) is added to the mixture via a dry-ice condenser. Thesolid dissolves completely. CH₂═C(CF₃)CF₂OSO₂F (49 g) is added dropwise.The resulting mixture is stirred at room temperature for 3 hours. Themixture is then distilled, yielding a liquid, which is redistilled(spinning band column) to give 36.3 g of CH₂═C(CF₃)CF₂OCF(CF₃)₂, b.pt.84-86° C., a yield of 55%. Less pure fractions are not included in theyield calculation.

¹⁹F NMR in with an external CFCl₃ standard: δ−65.3 (t, J=8 Hz, 3F);−66.6 (m, 2F); −81.0 (m, 6F); −146.4 (t, J=23 Hz, 1F) ppm. ¹H NMR δ 6.39(m) ppm. ¹³C NMR δ 101.5 (d & septet, J=269, 38 Hz); 117.1 (qd, J=258,32 Hz); 118.6 (t, J=274 Hz); 127.4 (m); 131.2 (m) ppm.

Example 8 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Hexafluoroisopropanol

A 100 ml flask is charged with tributylamine (15 g), diglyme (15 ml),and hexafluoroisopropanol (13.7 g) in a dry box. CH₂═C(CF₃)CF₂OSO₂F(20.0 g) is added dropwise at 3-12° C. The resulting mixture is stirredat room temperature for 2 hours. The mixture is then distilled to give aliquid, which is redistilled (spinning band column) giving 21.1 g orproduct, b.pt. 92-93° C. for a yield of 83%. Less pure fractions are notincluded in the yield calculation.

¹⁹F NMR in deuterochloroform with an external CFCl₃ standard: δ−65.3 (t,J=7 Hz, 2F); −70.8 (m, 2F); −74.0 (q, J=5 Hz, 6F) ppm. ¹H NMR indeuterochloroform: δ 4.99 (septet, J=5 Hz, 1 H); 6.37 (m, 2H). ¹³C NMRin deuterochloroform: δ 69.4 (septet, t, J=35, 4 Hz); 118.8 (t, J=269Hz); 120.2 (q, J=283 Hz); 120.6 (sextet, J=5 Hz); 130.9 (sextet, J=35Hz) ppm.

Example 9 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Trifluoroacetyl Fluoride

Trifluoroacetyl fluoride (6 g, 0.051 mole) is bubbled into a mixture ofKF (2.4 g, 0.041 mole) and dry diglyme (15 ml). The reaction mixture isstirred at 20° C. for 30 minutes and then CH₂═C(CF₃)CF₂OSO₂F (10 g,0.041 mile) is added gradually. The resulting mixture is stirred at 20°C. for 1 hour. Hexafluoroisobutylene is distilled from the reactionmixture and the residue is poured into water. The organic layer. isseparated, washed in turn with aqueous sodium bicarbonate solution andwater, and then dried over MgSO₄. Distillation gives3,3-Difluoro-3-pentafluoroethoxy-2-trifluoromethylpropene(CH₂═C(CF₃)CF₂OCF₂CF₃) (3.5 g, 31% yield, b.pt. 67° C.).

¹H NMR δ 5.65 (br.s, CH₂). ¹⁹F NMR δ−11 (t, 3 ¹F); −8.1 (tt, 2 ²F);J(¹F—²F)=13 Hz; J(³F—³F)=7 Hz. MS (m/z, species, intensity %): 280 [M]⁺(5); 261 [M-F]⁺ (15); 211 [M-CF₃]⁺ (90); 145 [M-C₂F₅O]⁺ (95);[CH₂═CCF₃]⁺ (80); 69 [CF₃]⁺ (100).C¹F₃—C(═CH₂)C²F₂—O—C³F₂C⁴F₃

Example 10 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Trifluoroethanol

A 100 ml flask is charged with tributylamine (15 g), diglyme (20 ml) ina dry box. 2,2,2-Trifluoroethanol (8.05 g) is added to the mixture.CH₂═C(CF₃)CF₂OSO₂F (19.5 g) is added dropwise while the mixture iscooled in an ice-water bath. The resulting mixture is stirred at roomtemperature for 3 hours. The mixture is then distilled to give a liquid,which is redistilled (spinning band column) giving 5.8 gCH₂═C(CF₃)CF₂OCH₂CF₃, b.pt. 85-86° C., a yield of 30%. Less purefractions are not included in the yield calculation.

¹⁹F NMR (CDCl₃) δ−65.4 (t, J=6 Hz, 3F); −72.7 (m, 2F); −75.0 (t, J=8 Hz,3F) ppm. ¹H NMR (CDCl₃): δ 4.30 (q, J=6 Hz, 2H); 6.25 (m, 1 H); 6.28 (m,1 H) ppm. ¹³C NMR (CDCl₃): δ 60.9 (qt, J=38, 6 Hz); 118.9 (t, J=264 Hz),121.4 (q, J=264 Hz); 122.5 (q, J=277 Hz); 126.7 (hex, J=5 Hz); 131.5(hex, J=33 Hz) ppm.

Example 11 Reaction of CH₂═C(CF₃)CF₂OSO₂F with1,1-Dihydroperfluoropropanol

A 100 ml flask is charged with tributylamine (15 g) and diglyme (20 ml)in a dry box. 1,1,-Dihydroperfluoropropanol (24.0 g) is added.CH₂═C(CF₃)CF₂OSO₂F (19.5 g) is added dropwise at 0-5° C. The resultingmixture is stirred at room temperature for 3 hours. The mixture is thendistilled to give a liquid, which is redistilled (spinning band column)giving 27.3 g CH₂═C(CF₃)CF₂OCH₂CF₂CF₃, b.pt. 54° C. at 200 mm Hg. Yieldis 58%. Less pure fractions are not included in the yield calculation.

¹⁹F NMR (CDCl₃): δ−65.4 (t, J=6 Hz, 3F); −73.1 (m, 2F); −84.2 (s, 3F);−124.3 (t, J=11 Hz, 2F) ppm. ¹H NMR (CDCl₃): δ 4.40 (tq, J=12 Hz, 2H);6.27 (m, 1H); 6.29 (m, 1H) ppm. ¹³C NMR (CDCl₃): δ 59.9 (tt, J=29, 6Hz); 111.6 (tq, J=264, 38 Hz); 118.3 (qt, J=286, 35 Hz); 118.8 (t, J=265Hz); 120.6 (q, J=273 Hz); 126.7 (hex, J=5 Hz); 131.5 (6, J=33 Hz) ppm.

Example 12 Reaction of CH₂═C(CF₂CF₃)CF₂OSO₂F with (CF₃)₂CFO⁻

CH₂═C(CF₂CF₃)CF₂OSO₂F (5 g, 17 mmole) is added at 20° C. to (CF₃)₂CCFOK,prepared at 10° C. from freshly dried KF (3 g, 17.2 mmole),hexafluoroacetone (HFA) (3 g, 18 mmole) and dry diglyme (15 ml). Thereaction mixture is agitated for 1 hour at 20° C. and then poured intowater, the organic layer separating. The organic layer is washed withaqueous sodium bicarbonate solution, then water, after which it is driedover (MgSO₄). Distillation of the reaction mixture givesCH₂═C(CF₂CF₃)CF₂OCF(CF₃)₂ (4 g, 62% yield, b.pt. 118-120° C.). Thisexample demonstrates that the fluorosulfates of the higher homolog ofhexafluoroisobutylene react with nucleophiles under the same mildconditions that characterize the reactions of CH₂═C(CF₃)CF₂OSO₂F.

¹⁹F NMR δ−8 (tth, 2 ³F); 7.9 (m, 3 ¹F); 38.2 (m, 2 ²F); 5 (dt, 6F); 70(th, 1 ⁴F); J(³F—³F)=33 Hz, J(³F—⁵F)=8 Hz. The superscripts that precede“F” identify the specific fluorine atoms on the compound, as shown inthe following structure:C¹F₃—C²F₂—C(═CH₂)—C³F₂OC⁴F(C⁵F₃)₂

Example 13 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Methanol

Triethylamine (2.5 g, 0.02 mole) is added gradually toCH₂═C(CF₃)CF₂OSO₂F (5 g, 0.02 mole) in dry methanol (10 ml) at 10° C.After 20 minutes the reaction mixture is poured into water. The organiclayer is separated, washed in turn in dilute aqueous HCl, water, sodiumbicarbonate solution, and water, and then dried over MgSO₄. Distillationof the dried mixture gives3,3-difluoro-3-methoxy-2-trifluoromethylpropene (1.8 g, 50% yield). Theisomer 1,1-difluoro-2-trifluoromethyl-3-methoxypropene (about 1%) andCH₂═C(CF₃)COOCH₃ (about 3%) are also detected by gas chromatography-massspectrometry (GC-MS).

3,3-difluoro-3-methoxy-2-trifluoromethylpropene: ¹H NMR δ 3.1 (s, CH₃);5.6 (s, CH) 5.7 (s, CH). ¹⁹F NMR δ−11.8 (t, CF₃); −2.45 (q, CF₂);J(CF₃—CF₃)=7 Hz. MS (m/z, species, intensity %): 176 [M]⁺ (100); 145[M-OCH₃]⁺ (75); 95 [CH₂═C(CF₃)]⁺ (30); 81 [CF₂OCH₃]⁺ (90); 69 [CF₃]⁺(30). 1,1-difluoro-2-trifluoromethyl-3-methoxypropene: MS (m/z, species,intensity %): 176 [M]⁺ (100); 145 [CF₂═C(CF₃)CH₂]⁺ (90); 107 [M-CF₃]⁺(60); 45 [CH₃OCH₂]⁺ (90); 69 [CF₃]⁺ (30). CH₂═C(CF₃)COOCH₃: MS (m/z,species, intensity %): 153 [M-H]⁺ (5); 123 [M-OCH₃]⁺ (100); 95[CH₂C(CF₃)]⁺ (30); 69 [CF₃]⁺ (40); 59 [COOCH₃]⁺ (10).

Example 14 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Pentafluorophenol

Pentafluorophenol (7.5 g, 0.040 mole) and triethylamine (4.5 g, 0.044mole) in dry ethyl ether (7 ml) are added gradually toCH₂═C(CF₃)CF₂OSO₂F (11 g, 0.045 mole) in ethyl ether (14 ml) at 20° C.The reaction mixture is agitated at 20° C. for 30 minutes and washed inturn with water, dilute aqueous HCl, water, sodium bicarbonate solution,and water and the resulting ether solution is dried over MgSO₄.Distillation of the dried mixture gives CH₂═C(CF₃)CF₂OC₆F₅ (9.8 g, 73%yield, b.pt. 86-88° C. at 20 mm Hg).

Elemental analysis: Found: C, 36.75%; H, 0.71%; F, 57.06%. Calculated:C, 36.58%; H, 0.61%; F, 57.93%. ¹H NMR: δ 5.28 (s), 5.36 (s). ¹⁹F NMR:δ−10.5 (CF₃); −6.5 (CF₂); 76 (F in ortho position); 81.5 (F in paraposition); 87.5 (F in meta position). MS (m/z, species, intensity %):328 [M]⁺ (16.8); 183 [C₆F₅O)]⁺ (25.6); 167 [C₆F₅]⁺ (100); 145[CH₂═C(CF₃)CF₂]⁺ (90); 95 [CH₂═C(CF₃)]⁺ (100).

Example 15 Reaction of CH₂═C(CF₃)CF₂OSO₂F with FSO₂CF₂COF

Under the conditions of Example 6 CH₂═C(CF₃)CF₂OCF₂CF₂SO₂F (11 g, 78.6%yield, b.pt. 124-125° C.) is obtained from KF (2.4 g, 0.041 mole),fluorosulfonoxydifluoroacetyl fluoride (FSO₂CF₂COF) (9 6, 0.05 mole) andCH₂═C(CF₃)CF₂OSO₂F (10 g, 0.041 mole) and diglyme (10 ml).

Elemental analysis: Found C, 20.62%; H, 0.69%; F, 55.28%. Calculated: C,20.93%; H, 0.58%; F, 55.23%. ¹H NMR: δ 6.05 (m). ¹⁹F NMR (ppm): δ−121(SO₂F); −11.5 (CF₃); −9 (CF₂O); 6 (CF₂); 36.5 (CF₂S). MS (m/z, species,intensity %): 344 [M]⁺ (7.9); 325 [M-F]⁺ (3.2); 261 [M-SO₂F]⁺ (2.3); 164(C₂F₄SO₂F]⁺ (45); 161 [CH₂═C(CF₃)CF₂O]⁺ (15.6); 145 [CH₂═C(CF₃)CF₂]⁺(99); 95 [CH₂═C(CF₃)]+(100); 69 [CF₃]⁺ (100).

Example 16 Reaction of CH₂═C(CF₂OSO₂F)₂ with FSO₂CF₂COF

CH₂═C(CF₂OSO₂F)₂ is added gradually to FSO₂CF₂CF₂OK, which is preparedfrom freshly dried KF (3.9 g, 0.067 mole) and FSO₂CF₂COF (12 g, 0.067mole) in dry diglyme (30 ml). The resulting mixture is stirred 3 hoursat 20° C. The reaction mixture is poured into water. The organic layeris washed with aqueous sodium bicarbonate, then water, and then driedover MgSO₄. Distillation gives CH₂═C(CF₃)CF₂OSO₂F (0.5 g) andCH₂═C(CF₂OCF₂CF₂SO₂F)₂ (9 g, 58% yield, b.pt. 95-96° C. at 15 mm Hg).

Elemental analysis: Found: C, 18.32%; H, 0.38%; F, 50.76%. Calculated:C, 18.32%; H, 0.46%; F, 50.81%. ¹H NMR: δ 6.68 (s). ¹⁹F NMR (CCl₄):δ−122.5 (2 ¹F); −10 (4 ⁴F); 5 (4 ²F); 35 (4 ²F). MS (m/z, species,intensity %): 534 [M]⁺ (0.1); 505 [M-F]⁺ (0.07); 325 [M-OCF₂CF₂SO₂F]⁺(22.8); 183 [CF₂CF₂SO₂F]⁺ (13.43); 145 [C₂F₃SO₂]⁺ (100); 101 [C₂F₄H]⁺(56.5); 100 [C₂F₄]⁺ (21.2); 83 [SO₂F]⁺ (1.2); 69 [CF₃]⁺ (18.7). In the¹⁹F NMR analysis the superscripts preceding the “F”s identify thefluorine atoms on the molecule:CH₂═C(C⁴F₂OC³F₂C²F₂SO₂ ¹F)₂

Example 17 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Chloride

CH₂═C(CF₃)CF₂OSO₂F (7.9 g, 0.032 mole) is added over 15 minutes to amixture of dry lithium chloride (LiCl) (1.5 g, 0.036 mole) and drydiglyme (15 ml) at 10° C. with stirring. The reaction mixture is workedup generally as described in other examples and two products, isomers,are identified by GC-MS and ¹⁹F NMR:2-Trifluoromethyl-3,3,-difluoro-3-chloropropene (CH₂═C(CF₃)CF₂Cl) (80%)and 1,1-difluoro-2-trifluoromethyl-3-chloropropene (CF₂═C(CF₃)CH₂Cl)(14%). The reaction mixture is stirred at 20° C. for an additional 30minutes. Analysis now shows the amounts of CH₂═C(CF₃)CF₂Cl andCF₂═C(CF₃)CH₂Cl to be present in a ratio of 30:1. The reaction mixtureis maintained at 0° C. for an additional 12 hours and nowCH₂═C(CF₃)CF₂Cl is the only product found. The reaction mixture isvacuum distilled to separate the CH₂═C(CF₃)CF₂Cl, which is thenredistilled to give 4.2 g of CH₂═C(CF₃)CF₂Cl (72.4% yield), b.pt. 46-48°C.

This example shows that the ratio of isomers is a function of thereaction time and that the methylene isomer predominates at longerreaction times over the difluoromethylene isomer. This is an indicationthat the methylene isomer is the more stable isomer at the temperaturesused in this example.

CH₂═C(CF₃)CF₂Cl: ¹H NMR: δ 6.38 (m, and 6.32 m (CH₂). ¹⁹F NMR: δ−24.5(q, CF₂Cl); −12.7 (t, CF₃); J(CF₃—CF₂)=7 Hz. MS (m/z, species, intensity%): 180 [M]⁺ (0.2); 161 [M-F]⁺ (3.4); 145 [M-Cl]⁺ (100); 119 [C₂F₅]⁺(21); 111 [M-CF₃]⁺ (6.8); 95 [CH₂CCF₃]⁺ (31); 85 [CF₂Cl]⁺ (7.8); 75[CH═CCF₂]⁺ (20.4); 69 [CF₃] 22.4); 49 [CH₂Cl] (1.2).

CF₂═C(CF₃)CH₂Cl: ¹H NMR: δ 4.58 (CH₂Cl). ¹⁹F NMR: δ−16 (dd, CF₃); −4.5(q, 2F); −0.5 (q, ¹F); J(CF₃-1F)=9 Hz and J(CF₃1F)=19 Hz. Note: ¹F isthe vinyl fluorine on the dihydrochloromethyl side of the double bond.²F is the vinyl fluorine on the trifluoromethyl side of the double bond.

MS (m/z, species, intensity %): 180 [M]⁺ (6); 161 [M-F]⁺ (13); 145[M-Cl]⁺ (100); 119 [C₂F₅]⁺ (3); 111 [M-CF₃]⁺ (8); 95 [CH₂═CCF₃] (57.6);85 [CF₂Cl]⁺ (8.6); 76 [CH₂CCF₂] (25); 75 [CH═CCF₂]⁺ (61); 69 [CF₃]³⁰(50); 49 [CH₂Cl]+(8.7).

Example 18 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Bromide

CH₂═C(CF₃)CF₂OSO₂F (9 g, 0.037 mole) is added gradually to a mixture ofdry sodium bromide (NaBr) (4.5 g, 0.044 mole) and dry diglyme (15 ml) at10° C. with stirring. The reaction mixture is stirred at 20° C. for 20minutes and then worked up generally as described in other examples andtwo products, isomers, are identified by GC-MS and ¹⁹F NMR:2-Trifluoromethyl-3,3,-difluoro-3-bromopropene (CH₂═C(CF₃)CF₂Br) (67%)and 1,1-difluoro-2-trifluoromethyl-3-bromopropene (CF₂═C(CF₃)CH₂Br)(27%). The reaction mixture is vacuum distilled to separate theCH₂═C(CF₃)CF₂Br, which is then redistilled to give 5.5 g ofCH₂═C(CF₃)CF₂Cl (69% yield), b.pt. 69-71° C.

As in Example 17, the methylene and difluoromethylene isomers are foundand it is to be expected, as in Example 17, that if the reaction isextended, the predominance of the methylene isomer would increase.

CH₂═C(CF₃)CF₂Br: ¹H NMR: δ 6.38 m and 6.28 m (CH₂). ¹⁹F NMR: δ−29.2 (q,CF₂Br); −13 (t, CF₃); J(CF₃—CF₂)=7 Hz. MS (m/z, species, intensity %):205 [M-F]⁺ (6.9); 155 [M-CF₃]1.6); 145 [M-Br]⁺ (100); 129 [CF₂Br]⁺ (2);95 [CH₂═CCF₃]31.3); 93 [CH₂Br]29; 79 [Br]⁺ (2.3); 69 [CF₂]⁺ (24.7).

CF₂═C(CF₃)CH₂Br: ¹H NMR: δ 4.2 m (CH₂Br). ¹⁹F NMR: δ−15.9 (dd, CF₃: −5.2(q, 2F); −1.4 (q, 1F); J(CF₃—¹F)=10 Hz and J(CF₃—²F)=19 Hz. Note: ¹F isthe vinyl fluorine on the dihydrobromomethyl side of the double bond. ²Fis the vinyl fluorine on the trifluoromethyl side of the double bond.

MS (m/z, species, intensity %): 226 [M]⁺ (1); 207 [M-F]⁺ (4.4); 155[M-CF₃]⁺ (1.3); 145 [M-Br]⁺ (100); 131 [CF₂Br]⁺ (1); 126 [M-C₂F₂]⁺(4.7); 119 [C₂F₅]⁺ (2.7); 95 [C₃H₂F₃]⁺ (33.9); 81 [Br]⁺ (2); 75 [C₃F₂H]⁺(23.2); 69 [CF₂]⁺ (20.2).

Example 19 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Iodide

CH₂═C(CF₃)CF₂OSO₂F (10 g, 0.04 mole) is added gradually to a mixture ofdry sodium iodide (Nal) (7 g, 0.047 mole) and dry diglyme (20 ml) at 10°C. with stirring. The reaction mixture is kept overnight and then pouredinto water. The organic layer is separated, washed with aqueous sodiumbicarbonate solution and then with water and then dried over MgSO₄.Distillation gives a mixture (6 g, 54%) of2-trifluoromethyl-3,3,-difluoro-3-iodopropene (CH₂═C(CF₃)CF₂I) (10%) and1,1-difluoro-2-trifluoromethyl-3-iodopropene (CF₂═C(CF₃)CH₂I) (90%), asshown by GC-MS and ¹⁹F NMR. B.pt. 98-99° C. The difluoromethylene isomerCF₂═C(CF₃)CH₂I predominates in this example. The experience withchloride as nucleophile (Example 17), indicates that reactionconditions, time in the case of Example 17, can be varied to control theratio of methylene to difluoromethylene isomer. Simple experimentationshould identify conditions at which iodide as nucleophile will yieldhigher amounts of methylene monomer.

CH₂═C(CF₃)CF₂I: ¹H NMR: δ 3.7 (CH₂I). ¹⁹F NMR: δ−15.5 (dd, CF₃); −5 (q,²F); −1.9 (q, ¹F); J(CF₃—¹F)=9 Hz and J(CF₃—²F)=18 Hz. Note: ¹F and ²Fidentify vinyl fluorines analogous to the identification in Examples 16and 17.

MS (m/z, species, intensity %): 272 [M]⁺ (12.9); 253 [M-F]⁺ (4.8); 241[M-CF]⁺ (0.05); 221 [M-CHF₂]⁺ (0.9); 203 [M-CF₃]⁺ (0.6); 177 [CF₂l]⁺(0.8) 145 [M-I]⁺ (100) 141 [CH₂I]⁺ (1.5); 127 [I] (38); 119 [C₂F₅]⁺ (1);100 [C₂F₄]⁺ (1); 69 [CF₃]⁺ (65); 31 [CF]⁺ (32.7).

CF₂═C(CF₃)CH₂I: ¹H NMR: δ 5.75 m and 5.85 m (CH₂). ¹⁹F NMR: δ −34.2 (q,CF₂I); −133 (t, CF₃); J(CF₃—CF₃)=7 Hz. MS (m/z, species, intensity %):272 [M]⁺ (0.1); 253 [M-F]⁺ (4.6); 177 [CF₂I]⁺ (1.5); 145 [M-I]⁺ (100);141 [CH₂I]⁺ (0.2); 127 [I]⁺ (22); 119 [C₂F₆]⁺ (2.5); 100 C₂F₄]⁺ (0.6);69 [CF₃]⁺ (58); 31 [CF]⁺ (48).

Example 20 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Fluoride

It will be noted that the product in this example ishexafluoroisobutylene, made by the reaction of CH₂═C(CF₃)CF₂OSO₂F withthe nucleophile fluoride ion. This would not normally be a practicalreaction: CH₂═C(CF₃)CF₂OSO₂F is made from hexafluoroisobutylene. Thereaction is included here to demonstrate how general the syntheticmethod of this invention is.

CH₂═C(CF₃)CF₂OSO₂F (5 g, 0.02 mole) is added to a mixture of KF (1.2 g,0.02 mole) and dry diglyme (10 ml) and stirred at 20° C. for 4 hours.¹⁹F NMR analysis shows the reaction mixture to contain 7.7% CH₂═C(CF₃)₂(hexafluoroisobutylene). More KF (2.4 g) is added and the resultingmixture stirred at 20° C. for 16 hours. The reaction mixture isdistilled, giving 2.5 g (73.5%) hexafluoroisobutylene.

Example 21 Reaction of CH₂═C(CF₂OSO₂F)₂ with Chloride

CH₂═C(CF₂OSO₂F)₂ (9 g, 0.028 mole) is added gradually to a stirredmixture of dry LiCl (2.5 g, 0.059 mole) and dry diglyme (20 ml) at 10°C. Fifteen minutes after addition is complete the reaction mixturecontains two isomers, CH₂═C(CF₂Cl)₂ and CF₂═C(CH₂Cl)CF₂Cl in the ratio79:14 (analysis by GC-MS and ¹⁹F NMR). The reaction mixture is stirredfor an additional 30 minutes at 20° C. The isomer ratio (CH₂═C(CF₂Cl)₂to CF₂═C(CH₂Cl)CF₂Cl) increased to 90:3. The reaction mixture is kept at20° C. for two additional days and then distilled, giving 4 g (73%) ofCH₂═C(CF₂Cl)₂, b.pt. 85-87° C. This example shows that the behavior ofthe difluorosulfate CH₂═C(CF₂OSO₂F)₂ with the chloride ion is similar tothat of the fluorosulfate CH₂═C(CF₃)CF₂OSO₂F. Longer reaction timepromotes formation of the methylene isomer over that of thedifluoromethylene isomer.

CH₂═C(CF₂Cl)₂: ¹H NMR: δ 6.46 br.s (CH₂). ¹⁹F NMR: δ−26.5 (s, CF₂Cl). MS(m/z, species, intensity %): 196 [M]⁺ (0.2); 177 [M-F]⁺ (2.6; 161[M-Cl]⁺ (100); 141 [M-HClF]⁺ (0.4); 126 [M-2Cl]⁺ (11.4); 111 [M-CF₂Cl]⁺(23.8); 93 [C₃F₃]⁺ (7.3}; 85 [CF₂Cl]⁺ (32.3); 75 [CF₂═C═CH]⁺ (59); 57[CF═C═CH₂]⁺ (245.4); 49 [CH₂Cl]⁺ (26).

CF₂═C(CH₂Cl)CF₂Cl: ¹H NMR: δ 3.85 br.s (CH₂Cl). ¹⁹F NMR: δ−29.5 (dd,CF₂Cl); −6.5 (t, ¹F); −0.4 (t, ²F); J(CF₂Cl-¹F)=34 Hz and J(CF₂Cl—²F)=9Hz. Note: ¹F. represents the vinyl fluorine cis to the chloromethylgroup. ²F represents the vinyl fluorine trans to the chloromethyl group.

MS (m/z, species, intensity %): 196 [M]⁺ (2.4); 177 [M-F]⁺ (1.7); 161[M-Cl]⁺ (100); 141 [M-HClF]⁺ (0.4); 126 [M-Cl]⁺ (11.4; 111 [M-CF₂Cl]⁺(23.8); 93 [C₃F₃]⁺ (7.2); 85 [CF₂Cl]⁺ (32.3); 75 CF₂═C═CH]⁺ (59); 57[CF═C═CH₂]⁺ (25.4); 49 [CH₂Cl]⁺ (26).

Example 22 Reaction of CH₂═C(CF₂OSO₂F)₂ with Iodide

CH₂═C(CF₂OSO₂F)₂ (15 g, 0.046 mole) is added gradually to a stirredmixture of dry NaI (16.5 g, 0.055 mole) and dry sulfolane (20 ml) at 10°C. with stirring. The reaction mixture is stirred at 20° C. for anadditional 20 minutes and poured into water. The organic layer isseparated, washed with aqueous sodium bicarbonate solution, washed withwater, and then dried over MgSO₄. Distillation gives CF₂═C(CH₂I)CF₂I(7.9 g, 57%) b.pt. 58-59° C. at 5 mm Hg. Though no methylene isomer,CH₂═C(CF₂I)CF₂I is found under these reaction conditions, experiencewith chloride as nucleophile (Example 20), indicates that reactionconditions, time in the case of Example 20, can be varied to control theratio of methylene to difluoromethylene isomer. Simple experimentationshould identify conditions at which iodide as nucleophile will yieldhigher amounts of methylene monomer.

¹H NMR: δ 3.2 br.s (CH₂I). ¹⁹ F NMR: δ−39.9 (dd, CF₂I); −9.5 (t, ²F);−2.1 (br.s, ¹F); J(CF₂I—¹F)=8 Hz and J(CF₂I—²F)=23 Hz. Note: ¹Frepresents the vinyl fluorine cis to the iodomethyl group. ²F representsthe vinyl fluorine trans to the iodomethyl group. MS (m/z, species,intensity %): 253 [M-I]⁺ (83.7); 177 [CF₂I]⁺ (2); 141 [CH₂I]⁺ (1.6);127[I]⁺ (31.4); 126 [C₂H₂F₄]⁺ (63.7); 100 [C₂F₄]⁺ (3.4); 75 [C₃HF₂]⁺(100); 69 [CF₃]⁺ (2.3); 31 [CF]⁺ (48).

Example 23 Reaction of CH₂═C(CF₃)CF₂OSO₂F with Cyanide

Sodium cyanide (2.4 g, 0.04 mole) is added gradually toCH₂═C(CF₃)CF₂OSO₂F (10 g, 0.04 mole) in dry acetonitrile (15 ml) at 10°C. The reaction mixture is stirred at 15° C. for 4 hours and then pouredinto water. The organic layer is separated, washed with water, and driedover MgSO₄. Distillation gives a mixture of compounds (3.5 g, 50%, b.pt.120-122° C.): CF₂═C(CF₃)CH₂CN (93%) and NC—CH₂CH(CF₃)₂ (7%).

CF₂═C(CF₃)CH₂CN: ¹H NMR: δ 2.74 dd (CH₂). ¹⁹F NMR: δ−15.1 dd (3 ¹F);−3.8 dtq (²F); J(¹F—²F)=21.5 Hz; J(¹F—³F)=12 Hz; J(³F—²F)=11.5 Hz;J(²F—CH₂)=2.5; J(¹F—CH₂)=2.5 Hz. MS (m/z, species, intensity %): 171[M]]30); 152 [M-F]⁺ (25); 102 [M-CF₃]⁺ (100); 75 [F₂C═C═CH]⁺ (25); 69[CF₃]⁺ (40). Note: ¹F represents the fluorines of the trifluoromethylgroup. ²F represents the vinyl fluorine that is cis to thetrifluoromethyl group. ³F represents the vinyl fluorine that is trans tothe trifluoromethyl group. Though no methylene isomer, CH₂═C(CF₃)CF₂CN,is found, experience with chloride as nucleophile (Example 17),indicates that reaction conditions, time in the case of Example 17, canbe varied to control the ratio of methylene to difluoromethylene isomer.Simple experimentation should identify conditions at which cyanide asnucleophile will yield higher amounts of methylene monomer.

NC—CH₂CH(CF₃)₂ ¹H NMR: δ 2.39 d (CH₂), 4.8 m (CH); J(H—F)=7.5 Hz;J(H—CH₂)=5.5 Hz. ¹⁹F NMR: δ−9.1 d (CF₃). MS (m/z, species, intensity %):172 [M-F]⁺ (30); 122 [M-CF₃]⁺ (100); 102 [M-CF₃-HF]⁺ (50); 77[F₂C═CH—CH₂]⁺ (50) 69 [CF₃]⁺ (90).

Example 24 Polymerization of CH₂═C(CF₃)CF₂OCH(CF₃)₂ with CF₂═CH₂

CH₂═C(CF₃)CF₂OCF(CF₃)₂ is made according the method of Example 8. A 75ml stainless steel autoclave chilled to <−20° C. is loaded with 11.6 gof CH₂═C(CF₃)CF₂OCH(CF₃)₂, 10 ml of CF₃CH₂CF₂CH₃ solvent, and 10 ml of˜0.17 M DP initiator in CF₃CFHCFHCF₂CF₃. The autoclave is chilled,evacuated and further loaded with ˜2 g of vinylidene fluoride (CF₂═CH₂).The autoclave is shaken overnight at room temperature. The resultinghazy fluid is dried under nitrogen, then under pump vacuum, and finallyfor 66 hours in a 75° C. vacuum oven, giving 12.9 g of white polymer.Fluorine NMR in hexafluorobenzene finds the polymer composition to be53.4 mole % vinylidene fluoride and 46.6 mole % CH₂═C(CF₃)CF₂OCH(CF₃)₂.Inherent viscosity in hexafluorobenzene at 25° C. is 0.116 dL/g. A smallsample is purified for DSC measurement by dissolving 0.5 g of polymer in3 g of H Galden ZT™ 85 solvent [HCF₂O(CF₂O)_(m)(CF₂CF₂O)nCF₂H],filtering the haze off using a 0.45 μm PTFE syringe filter (WhatmanAutovial®), evaporating off excess solvent, and drying in a 75° C.vacuum oven for 16 hours. The Tg is now 47° C. (10° C./min, N₂, secondheat).

Solution preparation: A hazy solution is made by rolling 2 g of polymerwith 18 g of H Galden™ ZT 85 solvent. The haze is removed by filteringfirst through a bed of chromatographic silica in a 0.45 μm glass fibermicrofiber syringe filter (Whatman Autovial™), centrifuging at 15000rpm, and finally filtering again through a 0.2 μm PTFE syringe filter(Gelman Acrodisc CR). Evaporation of 119.2 mg of this solution on aglass slide gave a clear film weighing 8.5 mg (solution ˜7 wt % insolids).

Example 25 Polymerization of CH₂═C(CF₃)CF₂OCF(CF₃)₂ with CF₂═CH₂

CH₂═C(CF₃)CF₂OCF(CF₃)₂ is made according the method of Example 7. A 110ml stainless steel autoclave chilled to <−20° C. is loaded with 26 g ofCH₂═C(CF₃)CF₂OCF(CF₃)₂, 25 ml of CF₃CFHCFHCF₂CF₃ solvent, and 10 ml of˜0.17 M DP initiator in CF₃CFHCFHCF₂CF₃. The autoclave is chilled,evacuated and further loaded with ˜5 g of vinylidene fluoride (CF₂═CH₂).The autoclave is shaken overnight at room temperature. The resultingviscous fluid is dried under nitrogen, then under pump vacuum, andfinally for 88 hours in a 75° C. vacuum oven, giving 26.7 g of whitepolymer. Fluorine NMR run in hexafluorobenzene finds the polymercomposition to be 51 mole % CH₂═C(CF₃)CF₂OCF(CF₃)₂ and 49 mole %CH₂═CF₂.

DSC, 10° C./min, N₂, 2nd heat, neither Tg nor Tm detected InherentViscosity, hexafluorobenzene, 25° C.: 0.083 Solution preparation: Aclear, colorless solution is made by rolling 2 g of polymer with 18 g ofH Galden™ ZT 85 solvent and passing through a 0.45 μm glass fibermicrofiber syringe filter (Whatman Autovial™).

1. A compound having the formula CH₂═C(R)CF₂X, wherein R is a linearfluoroalkyl group comprised of 1 to 10 carbon atoms and may containether oxygen, or R is a branched or a cyclic fluoroalkyl group comprisedof 2 to 10 carbon atoms and may contain ether oxygen and X isOCF₂(CF(CF₃)—O—CF₂)_(n)CF₂SO₂F where n=0-5.
 2. A compound having theformula CH₂═C(R)CF₂X, wherein R is a linear fluoroalkyl group comprisedof 1 to 10 carbon atoms and may contain ether oxygen, or R is a branchedor a cyclic fluoroalkyl group comprised of 2 to 10 carbon atoms and maycontain ether oxygen and X is cyanide.
 3. A compound having the formulaCH₂═C(R)CF₂X, wherein R is a linear fluoroalkyl group comprised of 1 to10 carbon atoms and may contain ether oxygen, or R is a branched or acyclic fluoroalkyl group comprised of 2 to 10 carbon atoms and maycontain ether oxygen and X is R′_(m)CH_(n)O wherein m=0 to 3 and n=3 to0 and m+n=3, and R′ is selected from the group consisting of alkyl,fluoroalkyl, and perfluoroalkyl.
 4. The compound of claim 3 wherein ifthere is a plurality of R′ groups, they are independently selected fromsaid group.
 5. The compound of claim 4 wherein said alkyl, fluoroalkyl,and perfluoroalkyl may be a linear and may contain ether oxygen andcontain 1 to 10 carbon atoms, or may be branched or cyclic and maycontain ether oxygen and contain from 2 to 10 carbon atoms and containfrom 1 to 10 carbon atoms.
 6. A compound having the formulaCH₂═C(R)CF₂X, wherein R is a linear fluoroalkyl group comprised of 1 to10 carbon atoms and may contain ether oxygen, or R is a branched or acyclic fluoroalkyl group comprised of 2 to 10 carbon atoms and maycontain ether oxygen and X is selected from the group consisting ofaryloxy, fluoroaryloxy, and perfluoroaryloxy.